Kenmore 80 Series Dryer taking too long to dry

I have a model 110.668325000 kenmore dryer and it takes 2 hours or more to dry a load. When load is checked after 20 minutes the clothes are warm but not hot as they were when it worked correctly. There's heat but not hot enough. Could it be a thermostat or thermistor thats bad?

OK, I reviewed the material on dryer vent length along with any obstruction and I'm ok here (Whirlpool), Thanks. It's a new 2 story house and the builder installed a rigit vent pipe (25 - 30 feet at most) in the interior wall 1st floor laundry room up through the 2nd floor and wall and out the roof. We've been living there 4 weeks now and my wife says it was working after we moved in. Prior to moving I pulled the dryer back panel and blew out any dust and lint. I remember prior to this happening when I would remove thee clothes when the dryer sounded, they would be hot ot the touch, but even after 1 hour in the dryer, they feel only warm. Any suggestions. thanks for your earlier quick reply.

Thank You. Ok, I spent a little time on the dryer again yesterday. I removed the rear panel and took off the lint trap and its housing, a little lint so I cleaned everything again and reassembled. I left off the rear panel and plugged the dryer back in. With no load in dryer I turned on the dryer and looking down through a hole at the top of the heating coil housing I could observe the heating coil. After I pressed the start button, about 5 seconds later the coil was glowing red, it stayed on for about 50 seconds and then went off for 65 seconds, it came back on for 35 seconds and off again for about 75 seconds and then on again for about 30 seconds and kept repeating this cycle with about the same time durations. I remember reading something about the heating cycle but though it "the coil" was on for several minutes before going off. Anyways, what's my next step? Thanks

** I remember reading something about the heating cycle but though it "the coil" was on for several minutes before going off. **

That is usually true but without a load it is difficult to say if it is normal. However, the element also needs proper air flow across it or it will overheat and trip the safety thermostat on the heater housing. My guess is that is what you may be seeing with the fast cycling.

Have you tried running a load with the venting totally removed from the dryer to see if drying improves yet? Doing so will at least rule out the venting as a possibility. You can then move onto a malfunction in the dryer itself.

My Kenmore dryer dries but takes a long time I cleaned out the vents but new duct tot he rear and cleaned out the back of the dryer after it was removed. they was lint in the bottom of the vent duct that screws onto the dryer I cleaned it. now ill see if it works. if that does not work what do

BV001855

10:35PM | 08/18/13

Similar problem same basic unit. 240 V.
Gets not too hot, on high.
Medium low virtually not at all (but a bit).
Takes forever.
It has run for 8 years with the vent it has. I did disconnect and clean vents all the way out. Made sure no new kinks.
Did general clean up on everything. The vent to the outside shows it is moving air (even slightly warm).

I would think an electric heating unit would either be all on or not. What choices?